App not installed - Solution needed!

I work for a major bank in the UK and we have an internal application that we can download for colleagues to access our intranet through our mobile devices.

The application is not listed on Play Store and can only be downloaded through a website. I have done so and followed the instructions on the website to download and install it on my S8 but I have recevied the same message every time I have tried to install it - "App not installed. The package conflicts with an existing package by the same name.".

There is no such other app installed on my device, I have factory reset it! I have tried so many suggestions that I have found on the Internet an nothing works! Could you please explain to me how can we work around this problem and why is this happening in the first place?

I understand that but I don't believe that my employer would risk its employees security by asking them to install an official app that has already been probably installed by more than 50,000 employees.

If there is a way to bypass the current problem, please share it with me as I would like to resolve it from my side...

It seems that Play Protect can stop apps from being installed into the system. You can go to the Play Store -> Three Lines on the left to pull up options menu -> Play Protect. Turn the settings Off, Install the apps and turn Play Protect back on. Although it is not recommended, that seems to be the only way to do it.